1. Field of the Invention
The present invention relates to earphone devices. For example, the present invention may be applied to an earplug type earphone device in which a sound tube is inserted to an external auditory meatus with an earpiece interposed therebetween.
2. Description of the Related Art
An earphone device typically vibrates a diaphragm disposed in a driver unit accommodated in a housing (a casing of the earphone device) in accordance with audio signals supplied from a portable music player or the like, varies a compression state of air, and thus generates sound corresponding to the audio signals.
For example, according to a lateral in-the-ear earphone device, a housing of the earphone device is supported by a tragus and an antitragus of a user, so that the earphone device fits in an ear of the user (for example, see Japanese Examined Patent Application Publication No. 6-81351).
In the above earphone device, since the shape of a pinna varies from person to person, a gap may be present between the housing and an external auditory meatus when the user wears the earphone device, resulting in leakage of sound through the gap.
In addition, in the above earphone device, since the shapes of the tragus and the antitragus vary from person to person, the user may not support the housing by the tragus and the antitragus, resulting in deterioration in fitting comfortability such as that fitting state is not maintained for a long time.
Meanwhile, according to a vertical in-the-ear earphone device, a diaphragm is arranged to directly oppose the entrance of the external auditory meatus of the user, and hence, the shape around the entrance of the external auditory meatus less influences the sound. Accordingly, such an earphone device may provide stable, high-quality sound to the user (for example, see Japanese Examined Patent Application Publication No. 6-59120).
In the above earphone device, a holder, such as a band or a hanger, is used for holding the earphone device when the user wears the earphone device, resulting in lack of portability. Also, the band is located over the top of the head thereby making the user's hair untidy.
To address the disadvantages with the lateral in-the-ear and the vertical in-the-ear earphone devices, as shown in FIGS. 15A to 15C, there is provided an earplug type earphone device 30 which includes an earpiece 31 having a profile corresponding to the external auditory meatus when the user wears the earphone device 30, a substantially cylindrical sound guide tube 32 provided in the earpiece 31, a substantially spherical housing 33 in which the sound guide tube 32 is mounted, a cord retainer 34 integrally provided with the housing 33, and a cord 7 connected to a driver unit (not shown) provided in the housing 33.
FIG. 15A is a lateral elevational view showing the earphone device 30 in the Y-Z plane. FIG. 15B is a rear elevational view showing the earphone device 30 in the X-Z plane. FIG. 15C is a bottom plan view showing the earphone device 30 in the X-Y plane.
The housing 33 vibrates a diaphragm disposed in the driver unit in accordance with audio signals supplied through the cord 7, and thus generates sound corresponding to the audio signals.
The sound guide tube 32 protrudes from the center portion of a front surface of the housing 33, and when the user wears the earphone device 30, the sound guide tube 32 is inserted to the external auditory meatus with the earpiece 31 interposed therebetween, so that the sound output via the driver unit of the housing 33 is guided to the external auditory meatus.
The earpiece 31 is formed of flexible material so that its shape is freely deformable. Once the earpiece 31 is inserted to the external auditory meatus, the earpiece 31 is closely attached to the external auditory meatus, thereby maintaining the fitting state in which the earpiece 31 is closely attached to the user's ear, and providing gentle fitting.